Hitachi, Ltd.

Yoshifumi Takada

Masakazu Yamamoto

Masaaki Kamemura

In a multi-layer wiring board in which board wirings are arranged in a plurality of wiring layers so as to be connected via a through hole, two through holes are provided in parallel, and two through holes are connected therebetween in both end portions of the respective through holes or one end portion thereof by the wiring board.

Multi-layer wiring board

An interface circuit includes at least one signal processing circuit connected to a transmission line which is equipped with a terminal circuit having a resistor with a terminal voltage applied to at least one terminal, and includes an input circuit for inputting from the transmission line a signal to be processed in the signal processing circuit, or an output circuit for outputting a processed signal to the transmission line or an input and output circuit for inputting and outputting a signal. The input circuit or the output circuit or the input and output circuit are incorporated in the signal processing circuit. The input circuit or the output circuit or the input and output circuit are directly connected to the transmission line, wherein the output circuit has a push-pull circuit which is directly connected to the transmission line to receive an output signal from the signal processing circuit and to have a constant output impedance which is independent of an output from the output signal. An interface system having a signal processing circuit having he interface circuit in an interface-network is disclosed. Based on the above structure, reflection noise which occurs in the interface-network system is absorbed, with an improved focusing of a waveform, and power consumption is minimized during high-speed signal transmission.

Interface circuit and interface-network system using the same

In such a bidirectional signal transmission circuit in which the transmitter circuit of the logic circuit elements used in the conventional single end transmission circuit can be utilized by setting an impedance of an end circuit to be a value greater than a characteristic impedance of a transmission path, by shortening a length of the transmission path for connecting the end circuit with the logic circuit elements, and by increasing an amplitude of an input signal with utilization of a reflection wave produced by an impedance mismatching, such a signal transmission circuit where various types of transmission circuits such as a bidirectional signal transmission circuit and a single end transmission circuit are employed in a mixture form, can be made compact, and low power consumption can be achieved.

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Hadano, Japan

Yoshifumi Takada